Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 215
Filter
1.
J Hepatol ; 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38972484

ABSTRACT

BACKGROUND AND AIM: The induction of effective CD8+ T cells is thought to play a critical role in the functional cure of chronic hepatitis B (CHB). Additionally, the use of checkpoint inhibitors is being evaluated to overcome T cell dysfunction during CHB. APPROACH AND RESULTS: A chimpanzee adenoviral vector (ChAdOx1-HBV) and a Modified vaccinia Ankara boost (MVA-HBV) encoding the inactivated polymerase, core, and S region from a consensus genotype C HBV were studied. The trial enrolled 55 patients with virally-suppressed CHB virus infection and HBsAg <4,000 IU/mL Group 1 received MVA-HBV intramuscularly (IM) on Day 0 and 28, Group 2 received ChAdOx1-HBV on Day 0/MVA-HBV on Day 28 (VTP-300), Group 3 received VTP-300 + low-dose nivolumab (LDN) on Day 28, and Group 4 received VTP-300 plus LDN with both injections. VTP-300 alone and in combination with LDN was well tolerated with no treatment-related serious adverse events. Reductions of HBsAg were demonstrated in the VTP-300 group 2: 3 of 18 patients with starting HBsAg < 50 IU/ml had durable log10 declines > 0.7 log10 2 months post last-dose. Group 3 (N=18) had reductions in HBsAg of 0.76 log10 and 0.80 log10 3 (p<0.001) at 2 and 7 months post last dose. Two developed persistent non-detectable HBsAg levels. CD4+ and CD8+ antigen-specific T cell responses were generated and there was a correlation between IFN-y ELISpot response and HBsAg decline in Group 2. CONCLUSIONS: VTP-300 induced CD4+ and CD8+ T cells and lowered HBsAg in a subset of patients with baseline values below 100 IU/ml. The addition of LDN resulted in significant reduction in surface antigen. VTP-300 is a promising immunotherapeutic to move forward alone or in combination therapies. IMPACT AND IMPLICATIONS: The induction of potent, durable CD8+ T cells may be critical to achieving a functional cure in chronic hepatitis B virus infection. A prime-boost immunotherapeutic consisting of an adenoviral-vector encoding hepatitis B antigens followed by a pox virus boost was shown to induce CD8+ T cells and to lower HBsAg in CHB patients, either alone or more impactfully when administered in conjunction with a checkpoint inhibitor. The use of immunotherapeutics CLINTRIALS: NCT047789.

2.
Osteoarthritis Cartilage ; 31(7): 954-965, 2023 07.
Article in English | MEDLINE | ID: mdl-36893979

ABSTRACT

OBJECTIVE: To develop sets of core and optional recommended domains for describing and evaluating Osteoarthritis Management Programs (OAMPs), with a focus on hip and knee Osteoarthritis (OA). DESIGN: We conducted a 3-round modified Delphi survey involving an international group of researchers, health professionals, health administrators and people with OA. In Round 1, participants ranked the importance of 75 outcome and descriptive domains in five categories: patient impacts, implementation outcomes, and characteristics of the OAMP and its participants and clinicians. Domains ranked as "important" or "essential" by ≥80% of participants were retained, and participants could suggest additional domains. In Round 2, participants rated their level of agreement that each domain was essential for evaluating OAMPs: 0 = strongly disagree to 10 = strongly agree. A domain was retained if ≥80% rated it ≥6. In Round 3, participants rated remaining domains using same scale as in Round 2; a domain was recommended as "core" if ≥80% of participants rated it ≥9 and as "optional" if ≥80% rated it ≥7. RESULTS: A total of 178 individuals from 26 countries participated; 85 completed all survey rounds. Only one domain, "ability to participate in daily activities", met criteria for a core domain; 25 domains met criteria for an optional recommendation: 8 Patient Impacts, 5 Implementation Outcomes, 5 Participant Characteristics, 3 OAMP Characteristics and 4 Clinician Characteristics. CONCLUSION: The ability of patients with OA to participate in daily activities should be evaluated in all OAMPs. Teams evaluating OAMPs should consider including domains from the optional recommended set, with representation from all five categories and based on stakeholder priorities in their local context.


Subject(s)
Osteoarthritis, Hip , Osteoarthritis, Knee , Humans , Osteoarthritis, Knee/therapy , Osteoarthritis, Hip/therapy , Consensus , Health Personnel , Surveys and Questionnaires , Delphi Technique
3.
New Microbes New Infect ; 45: 100959, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35242337

ABSTRACT

•Omicron variant continues to progress in Senegal with the appearance of new contaminations.•IRESSEF detected the first positive case of the Omicron variant on Friday, December 3, 2021.•Since this date, the number of Omicron variant infections has increased over the weeks.•Molecular surveillance of the Omicron variant is carried out in real time to inform the medical authorities.

4.
Arch Pediatr ; 29(1): 21-26, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34753634

ABSTRACT

INTRODUCTION: Several pediatric studies have demonstrated that therapy using a conventional insulin pump improves glycemic control and quality of life. At the beginning of this study, a new tubeless insulin pump, Omnipod®, had recently been marketed in France. OBJECTIVES: Analyze the response of adolescents treated with multiple injections to the proposal to use this new medical device and compare both the quality of life and the glycemic control of adolescents according to their choice. MATERIAL AND METHODS: This was a prospective, observational study of adolescents aged 10-17 years who had type 1 diabetes for more than 1 year, all treated with multi-injection insulin delivery according to a basal-bolus regimen. They were separated into three groups: group A choosing to use the Omnipod® system, group B taking the time to think before making a decision, and group C choosing to keep their multi-injection therapy. The three groups were compared according to their quality of life with validated tools and glycemic control. RESULTS: Groups were formed with 30 (25%) patients in group A, 55 patients (45%) in group B, and 36 patients (30%) in group C. As to the WHO Well-Being Index, no significant difference appeared in the study for the patients in the three groups. An increased treatment satisfaction score was found, evolving from 3.79 ± 0.68 to 4.36 ± 0.56, p = 0.002 (group A) and from 3.87 ± 0.7 to 4.16 ± 0.7, p = 0.032 (group B), with no significant change for group C (from 4.39 ± 0.6 to 4.31 ± 0.62, p = 0.582). The wish to change treatment score improved for group A (from 4.14 ± 0.88 to 1.68 ± 0.9; p < 0.001) and group B (from 3.51 ± 1.05 to 1.84 ± 1; p < 0.001), with no significant change for group C (from 1.81 ± 0 0.98 to 1.61 ± 0.8; p = 0.432). There was no significant difference regarding HbA1c rates in the three groups. CONCLUSION: There was no significant difference in quality-of-life scores between adolescents who chose to switch from multiple injection to the tubeless patch pump and those who retained multi-injection treatment, but increased satisfaction was observed in the former group.


Subject(s)
Diabetes Mellitus, Type 1/drug therapy , Hypoglycemic Agents/therapeutic use , Insulin Infusion Systems/psychology , Insulin/therapeutic use , Quality of Life/psychology , Adolescent , Blood Glucose/analysis , Diabetes Mellitus, Type 1/psychology , Female , Glycated Hemoglobin/analysis , Humans , Hypoglycemic Agents/administration & dosage , Insulin/administration & dosage , Male , Patient Satisfaction , Prospective Studies
5.
Afr. J. Clin. Exp. Microbiol ; 23(4): 369-377, 2022. tables, figures
Article in English | AIM (Africa) | ID: biblio-1396434

ABSTRACT

Background: Today, bacterial resistance is a public health challenge throughout the world, and infections caused by resistant bacteria are associated with increased morbidity, mortality and health care costs. The objective of this descriptive study is to determine the prevalence and distribution of multi-drug resistant (MDR) clinical bacteria isolates at the National Hospital of Zinder, Niger Republic in 2021. Methodology: We conducted a descriptive cross-sectional study of in- and out-patients from whose clinical samples' bacteria were isolated at the bacteriology unit of the laboratory. Bacteria were isolated from the clinical samples following standard aerobic cultures and identified using conventional biochemical test schemes. Antibiotic susceptibility testing (AST) was performed by the agar disk diffusion technique, and categorization of the isolates into sensitive, intermediate or resistant was done according to the recommendations of the Antibiogram Committee of the French Society of Microbiology (CA-SFM) 2020 version 1.2. MDR was defined as resistance to at least one antibiotic in three or more categories, while selected MDR bacteria such as ESBL was identified using double disk synergy test, and MRSA by cefoxitin disk diffusion test. Results: Seventy-seven (6.7%) bacterial species were isolated from 1153 clinical samples processed at the bacteriology unit of the hospital laboratory between June and December 2021, of which 65.0% (50/77) were members of the order Enterobacteriales. Escherichia coli represented 40.3% (40/77) of the isolated bacteria, Staphylococcus aureus 13.0% (10/77) and Pseudomonas aeruginosa 11.7% (9/77). The overall prevalence of MDR was 44.2% (34/77), including 61.8% (21/34) ESBL-producing Enterobacteriales (ESBL-E), 26.5% (9/34) multi-resistant P. aeruginosa and 11.7% (4/34) MRSA, with 67.6% (23/34) of the MDR isolates from outpatients. Resistance rates of the Enterobacteriales to ciprofloxacin, gentamicin, amikacin and imipenem were 62.0%, 52.0%, 38.0% and 8.0% respectively. Resistance rates of P. aeruginosa were 100.0%, 88.9%, 77.8%, 33.3%, 22.2%, and 22.2% respectively to ceftazidime, ticarcillin, imipenem, ciprofloxacin, levofloxacin, and amikacin. Resistance rates of S. aureus were 100.0%, 50.0%, 40.0%, 10.0%, 0% and 0% to penicillin G,erythromycin, cefoxitin, tetracycline, fusidic acid, and chloramphenicol respectively. ESBL-E were 47.6%,85.7% and 0% resistant to amikacin, ciprofloxacin and imipenem, and MRSA resistance rates were 75.0%, 75.0%, 50.0% and 0% to erythromycin, tetracycline, gentamicin, and chloramphenicol respectively. Conclusion: This study reports high prevalence of MDR bacteria, mainly ESBL-E, with concerning high resistance to carbapenem. Rational use of antibiotics and implementation of surveillance system for MDR bacteria must be implemented in order to limit the emergence and spread of MDR bacteria in Niger Republic.


Subject(s)
Humans , Outpatient Clinics, Hospital , Genes, MDR , Bacteria , Inpatient Care Units , Niger
7.
Ann Oncol ; 32(7): 896-905, 2021 07.
Article in English | MEDLINE | ID: mdl-33836265

ABSTRACT

BACKGROUND: Treatment of poor prognosis metastatic castration-resistant prostate cancer (mCRPC) includes taxane chemotherapy and androgen receptor pathway inhibitors (ARPI). We sought to determine optimal treatment in this setting. PATIENTS AND METHODS: This multicentre, randomised, open-label, phase II trial recruited patients with ARPI-naive mCRPC and poor prognosis features (presence of liver metastases, progression to mCRPC after <12 months of androgen deprivation therapy, or ≥4 of 6 clinical criteria). Patients were randomly assigned 1 : 1 to receive cabazitaxel plus prednisone (group A) or physician's choice of enzalutamide or abiraterone plus prednisone (group B) at standard doses. Patients could cross over at progression. The primary endpoint was clinical benefit rate for first-line treatment (defined as prostate-specific antigen response ≥50%, radiographic response, or stable disease ≥12 weeks). RESULTS: Ninety-five patients were accrued (median follow-up 21.9 months). First-line clinical benefit rate was greater in group A versus group B (80% versus 62%, P = 0.039). Overall survival was not different between groups A and B (median 37.0 versus 15.5 months, hazard ratio (HR) = 0.58, P = 0.073) nor was time to progression (median 5.3 versus 2.8 months, HR = 0.87, P = 0.52). The most common first-line treatment-related grade ≥3 adverse events were neutropenia (cabazitaxel 32% versus ARPI 0%), diarrhoea (9% versus 0%), infection (9% versus 0%), and fatigue (7% versus 5%). Baseline circulating tumour DNA (ctDNA) fraction above the cohort median and on-treatment ctDNA increase were associated with shorter time to progression (HR = 2.38, P < 0.001; HR = 4.03, P < 0.001). Patients with >30% ctDNA fraction at baseline had markedly shorter overall survival than those with undetectable ctDNA (HR = 38.22, P < 0.001). CONCLUSIONS: Cabazitaxel was associated with a higher clinical benefit rate in patients with ARPI-naive poor prognosis mCRPC. ctDNA abundance was prognostic independent of clinical features, and holds promise as a stratification biomarker.


Subject(s)
Prostatic Neoplasms, Castration-Resistant , Androgen Antagonists/therapeutic use , Androstenes , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Benzamides , Humans , Male , Nitriles , Phenylthiohydantoin , Prednisone/adverse effects , Prognosis , Prostatic Neoplasms, Castration-Resistant/drug therapy , Taxoids/therapeutic use , Treatment Outcome
8.
Nat Commun ; 12(1): 457, 2021 01 19.
Article in English | MEDLINE | ID: mdl-33469031

ABSTRACT

Complex-valued neural networks have many advantages over their real-valued counterparts. Conventional digital electronic computing platforms are incapable of executing truly complex-valued representations and operations. In contrast, optical computing platforms that encode information in both phase and magnitude can execute complex arithmetic by optical interference, offering significantly enhanced computational speed and energy efficiency. However, to date, most demonstrations of optical neural networks still only utilize conventional real-valued frameworks that are designed for digital computers, forfeiting many of the advantages of optical computing such as efficient complex-valued operations. In this article, we highlight an optical neural chip (ONC) that implements truly complex-valued neural networks. We benchmark the performance of our complex-valued ONC in four settings: simple Boolean tasks, species classification of an Iris dataset, classifying nonlinear datasets (Circle and Spiral), and handwriting recognition. Strong learning capabilities (i.e., high accuracy, fast convergence and the capability to construct nonlinear decision boundaries) are achieved by our complex-valued ONC compared to its real-valued counterpart.

9.
J Cardiovasc Comput Tomogr ; 13(3): 26-33, 2019.
Article in English | MEDLINE | ID: mdl-30796003

ABSTRACT

OBJECTIVES: The purpose of this study was to analyze the prognostic value of dynamic CT perfusion imaging (CTP) and CT derived fractional flow reserve (CT-FFR) for major adverse cardiac events (MACE). METHODS: 81 patients from 4 institutions underwent coronary computed tomography angiography (CCTA) with dynamic CTP imaging and CT-FFR analysis. Patients were followed-up at 6, 12, and 18 months after imaging. MACE were defined as cardiac death, nonfatal myocardial infarction, unstable angina requiring hospitalization, or revascularization. CT-FFR was computed for each major coronary artery using an artificial intelligence-based application. CTP studies were analyzed per vessel territory using an index myocardial blood flow, the ratio between territory and global MBF. The prognostic value of CCTA, CT-FFR, and CTP was investigated with a univariate and multivariate Cox proportional hazards regression model. RESULTS: 243 vessels in 81 patients were interrogated by CCTA with CT-FFR and 243 vessel territories (1296 segments) were evaluated with dynamic CTP imaging. Of the 81 patients, 25 (31%) experienced MACE during follow-up. In univariate analysis, a positive index-MBF resulted in the largest risk for MACE (HR 11.4) compared to CCTA (HR 2.6) and CT-FFR (HR 4.6). In multivariate analysis, including clinical factors, CCTA, CT-FFR, and index-MBF, only index-MBF significantly contributed to the risk of MACE (HR 10.1), unlike CCTA (HR 1.2) and CT-FFR (HR 2.2). CONCLUSION: Our study provides initial evidence that dynamic CTP alone has the highest prognostic value for MACE compared to CCTA and CT-FFR individually or a combination of the three, independent of clinical risk factors.


Subject(s)
Computed Tomography Angiography/methods , Coronary Angiography/methods , Coronary Artery Disease/diagnostic imaging , Coronary Vessels/diagnostic imaging , Fractional Flow Reserve, Myocardial , Myocardial Perfusion Imaging/methods , Aged , Artificial Intelligence , Asia , Coronary Artery Disease/mortality , Coronary Artery Disease/physiopathology , Coronary Artery Disease/therapy , Coronary Vessels/physiopathology , Europe , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Prognosis , Prospective Studies , Radiographic Image Interpretation, Computer-Assisted , Registries , Risk Assessment , Risk Factors , United States
10.
J Med Virol ; 89(3): 484-488, 2017 03.
Article in English | MEDLINE | ID: mdl-26705258

ABSTRACT

The aim of this pilot study was to analyze the Hepatitis C Virus (HCV) genotypes circulating in Senegal among Drug User (DUs), using Dried Blood Spots (DBS) as RNA source for molecular assays. Heroin and/or cocaine users (n = 506) were recruited in Dakar from April to July 2011, using a Respondent Driven Sampling (RDS) method. DBS preparation consisted of five drops of whole blood from finger applied to a Whatman paper card. HCV infection was screened by the detection of anti-HCV antibodies, using a rapid immune-chromatographic test. HCV RNA was quantified on anti-HCV positive DBS, using the Abbott RealTime HCV® Genotyping was performed on DBS with detectable viral load with Versant® HCV Genotype 2.0 Assay (LiPA) and Abbott RealTime HCV Genotype II assay®. Among the 506 participants, 120 were tested as positive for anti-HCV antibodies and their samples were analyzed for HCV RNA viral load and genotype. Out of the 120 DBS tested, HCV RNA was detected on 25 (20.8%). The median viral load was 15,058 IU/ml (ranging from 710 to 766,740 IU/ml). All positive DBS were suitable for the genotyping assay, that showed a predominance of genotype 1 (21/25) including 16 genotypes 1a and 5 genotypes 1b. HCV genotype 1 prevails in a DU population in Dakar. DBS could be useful for HCV RNA genotyping, but optimal storage conditions should required avoiding RNA impairment. Acknowledging this limitation, DBS could be a great interest for detecting and genotyping HCV viremic patients. J. Med. Virol. 89:484-488, 2017. © 2015 Wiley Periodicals, Inc.


Subject(s)
Drug Users , Genotyping Techniques/methods , Hepacivirus/classification , Hepatitis C/virology , RNA, Viral/blood , Specimen Handling/methods , Adolescent , Adult , Blood/virology , Desiccation , Female , Hepacivirus/genetics , Hepacivirus/isolation & purification , Hepatitis C/diagnosis , Humans , Male , Middle Aged , Pilot Projects , Senegal , Young Adult
11.
Osteoarthritis Cartilage ; 25(1): 76-84, 2017 01.
Article in English | MEDLINE | ID: mdl-27539889

ABSTRACT

OBJECTIVE: To determine the association of different types of meniscal pathology with knee pain, bone marrow lesion (BML) volume, and end-stage knee osteoarthritis (esKOA). DESIGN: Participants were selected from an ancillary project to the Osteoarthritis Initiative (OAI) who had at least one knee with symptomatic osteoarthritis. Baseline magnetic resonance images (MRI) were evaluated for meniscal pathology using a modified International Society of Arthroscopy, Knee Surgery, and Orthopaedic Sports Medicine (ISAKOS) classification system. We collapsed 10 types of meniscal pathology into five categories: normal, intrameniscal signal, morphological deformity/extrusion (altered meniscal shape and/or extrusion but no apparent substance loss), tear, and maceration. Outcomes included Western Ontario and McMaster Universities osteoarthritis index (WOMAC) knee pain and BML volume at baseline and after 2 years. We defined the prevalence of esKOA based on a validated algorithm. We performed logistic regression and adjusted for age, sex, and body mass index (BMI). RESULTS: The 463 participants (53% male) included in the analysis had mean age 63 (9.2) years, BMI 29.6 (4.6) kg/m2, and 71% had Kellgren-Lawrence grade ≥2. Morphological deformity/extrusion and maceration, but no other types of meniscal pathology, were associated with BML volume (morphological deformity/extrusion odds ratio [OR] = 2.47, 95% CI: 1.49, 4.09, maceration OR = 5.85, 95% CI: 3.40, 10.06) and change in BML volume (morphological deformity/extrusion OR = 2.17, 95% CI: 1.37, 3.45, maceration OR = 3.12, 95% CI: 1.87, 5.19). Only maceration was associated with baseline WOMAC knee pain (OR = 2.82, 95% CI: 1.79, 4.43) and prevalence of esKOA (OR = 7.53, 95% CI: 4.25, 13.31). CONCLUSIONS: Based on MRI, morphologic deformity/extrusion and maceration rather than intrameniscal signal or tear were associated with osteoarthritis severity and progression, which highlights the importance of differentiating distinct types of meniscal pathology.


Subject(s)
Meniscus/pathology , Osteoarthritis, Knee/pathology , Arthralgia/diagnostic imaging , Arthralgia/pathology , Female , Humans , Knee Joint/diagnostic imaging , Knee Joint/pathology , Magnetic Resonance Imaging , Male , Meniscus/diagnostic imaging , Middle Aged , Osteoarthritis, Knee/classification , Osteoarthritis, Knee/diagnostic imaging
12.
Opt Express ; 24(19): 21744-51, 2016 Sep 19.
Article in English | MEDLINE | ID: mdl-27661912

ABSTRACT

Conventional silicon photonic integrated circuits do not normally possess memory functions, which require on-chip power in order to maintain circuit states in tuned or field-configured switching routes. In this context, we present an electrically programmable add/drop microring resonator with a wavelength shift of 426 pm between the ON/OFF states. Electrical pulses are used to control the choice of the state. Our experimental results show a wavelength shift of 2.8 pm/ms and a light intensity variation of ~0.12 dB/ms for a fixed wavelength in the OFF state. Theoretically, our device can accommodate up to 65 states of multi-level memory functions. Such memory functions can be integrated into wavelength division mutiplexing (WDM) filters and applied to optical routers and computing architectures fulfilling large data downloading demands.

13.
Hong Kong Med J ; 22(3): 210-5, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27101790

ABSTRACT

INTRODUCTION: Screening mammogram can decrease the mortality of breast cancer. Studies show that women avoid mammogram because of fear of pain, diagnosis, and radiation. This study aimed to evaluate the effectiveness of a radiolucent pad (MammoPad; Hologic Inc, Bedford [MA], US) during screening mammogram to reduce pain in Chinese patients and the possibility of glandular dose reduction. METHODS: This case series was conducted in a private hospital in Hong Kong. Between November 2011 and January 2012, a total of 100 Chinese patients were recruited to our study. Left mammogram was performed without MammoPad and served as a control. Right mammogram was performed with the radiolucent MammoPad. All patients were then requested to complete a simple questionnaire. The degree of pain and discomfort was rated on a 0-10 numeric analogue scale. Significant reduction in discomfort was defined as a decrease of 10% or more. RESULTS: Of the 100 patients enrolled in this study, 66.3% of women reported at least a 10% reduction in the level of discomfort with the use of MammoPad. No statistical differences between age, breast size, and the level of discomfort were found. CONCLUSION: The use of MammoPad significantly reduced the level of discomfort experienced during mammography. Radiation dose was also reduced.


Subject(s)
Breast Neoplasms/diagnostic imaging , Mammography/methods , Pain Management/instrumentation , Pain/prevention & control , Adult , Aged , Early Detection of Cancer/methods , Female , Hong Kong , Humans , Mammography/adverse effects , Middle Aged , Pain Measurement , Surveys and Questionnaires
14.
Opt Express ; 23(21): 26940-51, 2015 Oct 19.
Article in English | MEDLINE | ID: mdl-26480355

ABSTRACT

In this study, slot waveguide ring resonators patterned on a silicon-on-insulator (SOI) wafer and coated with an atomic layer deposited nanolaminate consisting of alternating layers of tantalum pentoxide and polyimide were fabricated and characterized. To the best of our knowledge, this is the first demonstration of atomic layer deposition (ALD) of organic materials in waveguiding applications. In our nanolaminate ring resonators, the optical power is not only confined in the narrow central air slot but also in several parallel sub-10 nm wide vertical polyimide slots. This indicates that the mode profiles in the silicon slot waveguide can be accurately tuned by the ALD method. Our results show that ALD of organic and inorganic materials can be combined with conventional silicon waveguide fabrication techniques to create slot waveguide ring resonators with varying mode profiles. This can potentially open new possibilities for various photonic applications, such as optical sensing and all-optical signal processing.

15.
Opt Express ; 23(21): 27683-9, 2015 Oct 19.
Article in English | MEDLINE | ID: mdl-26480430

ABSTRACT

Ultraviolet photodetector with p-n heterojunction is fabricated by magnetron sputtering deposition of n-type indium gallium zinc oxide (n-IGZO) and p-type nickel oxide (p-NiO) thin films on ITO glass. The performance of the photodetector is largely affected by the conductivity of the p-NiO thin film, which can be controlled by varying the oxygen partial pressure during the deposition of the p-NiO thin film. A highly spectrum-selective ultraviolet photodetector has been achieved with the p-NiO layer with a high conductivity. The results can be explained in terms of the "optically-filtering" function of the NiO layer.

16.
Rev Med Brux ; 36(1): 10-3, 2015.
Article in French | MEDLINE | ID: mdl-25856966

ABSTRACT

OBJECTIVE: To establish the respective prevalence of microalbuminuria and dyslipidemia and to evaluate their association with diabetes type 2. ANALYZE DATA: Prospective study of 195 type 2 diabetic subjects (125 women and 70 men) from a hospital in the city of Dakar (Senegal) for a check-up of diabetes. Age and sex were determined ; fasting blood glucose, glycated hemoglobin, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides and micro- albuminuria were measured. RESULTS: In this study, the mean age of patients was 57.9 ± 11.1 years. Age, glycated hemoglobin and microalbuminuria were significantly higher in women than in men (P < 0.01 ; P < 0.03 ; P < 0.01 respectively). The prevalence of microalbuminuria is 48.7% and that of dyslipidemia is 41.1%. Glycated hemoglobin is higher in subjects with microalbuminuria than in patients with normal microalbuminuria with a statistically significant difference (P < 0.001). There is a strong correlation (R = 0.82) between glycated hemoglobin and microalbuminuria, 1% increase in HbA1c corresponding approximately to an increase of 39.7 mg/I of microalbuminuria. CONCLUSION: Microalbuminuria and dyslipidemia are frequently found in type 2 diabetes, but the pathophysiological mechanisms of the association are not well known.


Subject(s)
Albuminuria/urine , Diabetes Mellitus, Type 2/metabolism , Dyslipidemias/blood , Adult , Age Factors , Blood Glucose/analysis , Cholesterol/blood , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/urine , Female , Glycated Hemoglobin/analysis , Humans , Hypercholesterolemia/blood , Hypertriglyceridemia/blood , Male , Middle Aged , Prospective Studies , Sex Factors , Triglycerides/blood
17.
Opt Express ; 22(18): 21800-5, 2014 Sep 08.
Article in English | MEDLINE | ID: mdl-25321555

ABSTRACT

In this paper we have designed, fabricated and characterized a high efficiency Silicon nitride grating coupler at 1490 nm. Distributed Bragg reflectors as bottom mirrors are employed to improve the coupling efficiency by reflecting the downward traveling light. The peak coupling efficiency obtained is about -2.5 dB and the 1-dB bandwidth is 53 nm. The fabrication process is CMOS-compatible and is ready to be integrated with photonic circuits.

18.
Opt Express ; 22(20): 24235-40, 2014 Oct 06.
Article in English | MEDLINE | ID: mdl-25321998

ABSTRACT

We report a novel lateral packaging approach using laser welding technique with angle polished fiber coupling to grating coupler embedded silicon photonic circuit. Measurements show the relax alignment tolerance for fiber packaging process. The packaging excess loss of 1.2 dB is achieved. The use of angle polished fiber for lateral fiber coupling enables an alternative way for cost-effective deployment of silicon photonics packaging in telecommunication systems.

19.
Opt Express ; 22(15): 17930-47, 2014 Jul 28.
Article in English | MEDLINE | ID: mdl-25089413

ABSTRACT

An ultra-compact electro-absorption (EA) modulator operating around 1.55-µm telecom wavelengths is proposed and theoretically investigated. The modulator is comprised of a stack of TiN/HfO2

20.
Opt Express ; 21(20): 23376-90, 2013 Oct 07.
Article in English | MEDLINE | ID: mdl-24104251

ABSTRACT

Silicon nitride waveguides provide low propagation loss but weak mode confinement due to the relatively small refractive index contrast between the Si3N4 core and the SiO2 cladding. On the other hand, metal-insulator-metal (MIM) plasmonic waveguides offer strong mode confinement but large propagation loss. In this work, MIM-like plasmonic waveguides and passive devices based on horizontal Cu-Si3N4-Cu or Cu-SiO2-Si3N4-SiO2-Cu structures are integrated in the conventional Si3N4 waveguide circuits using standard CMOS backend processes, and are characterized around 1550-nm telecom wavelengths using the conventional fiber-waveguide-fiber method. The Cu-Si3N4(~100 nm)-Cu devices exhibit ~0.78-dB/µm propagation loss for straight waveguides, ~38% coupling efficiency with the conventional 1-µm-wide Si3N4 waveguide through a 2-µm-long taper coupler, ~0.2-dB bending loss for sharp 90° bends, and ~0.1-dB excess loss for ultracompact 1 × 2 and 1 × 4 power splitters. Inserting a ~10-nm SiO2 layer between the Si3N4 core and the Cu cover (i.e., the Cu-SiO2(~10 nm)-Si3N4(~100 nm)-SiO2(~10 nm)-Cu devices), the propagation loss and the coupling efficiency are improved to ~0.37 dB/µm and ~52% while the bending loss and the excess loss are degraded to ~3.2 dB and ~2.1 dB, respectively. These experimental results are roughly consistent with the numerical simulation results after taking the influence of possible imperfect fabrication into account. Ultracompact plasmonic ring resonators with 1-µm radius are demonstrated with an extinction ratio of ~18 dB and a quality factor of ~84, close to the theoretical prediction.

SELECTION OF CITATIONS
SEARCH DETAIL